In a tunnel (hole) construction process, an internationally accepted tunnel boring machine construction method has the significant advantages of “high boring speed, low construction disturbance, high cavitation quality, high comprehensive economic and social benefits, construction safety and civilization and the like”, which can not be matched by a drilling and blasting construction method. At present, 30-40% of tunnels are dug by tunnel boring machines every year in the world, the number of the tunnels dug by the tunnel boring machines exceeds 1,000, the accumulated boring length exceeds 5,000 kilograms, and some international departments also explicitly stipulate that tunnels (holes) of more than 3 km must be constructed by adopting the tunnel boring machines. The tunnel boring machine construction method is an irresistible trend and a leading choice of worldwide tunnel (hole) engineering construction.
The tunnel boring machine construction method has poor adaptability to the geological conditions of large stratum change amplitude, unfavorable geological development and the like. Since existing tunnel construction period advanced prediction instruments and technologies can not previously detect and preprocess unfavorable geological conditions, the risks of geological hazards such as water and mud outburst, landslide and large deformation in the tunnel boring machine construction are higher, tunnel boring machines are easily stuck, damaged and scrapped, and even major accidents of casualties happen. Accordingly, technical research and equipment development for quantitative advanced prediction of unfavorable geology in front of the tunnel face in a complex boring machine construction environment are urgently needed for tunnel construction safety in the boring machine construction.
For advanced geological prediction technologies and detection devices, the essential difference between the tunnel boring machine construction and the drilling and blasting method construction lies in that: (1) a tunnel boring machine is huge and occupies most space behind the tunnel face, and a common excitation shot point and a common receiving system for seismic wave advanced prediction can not be arranged on the side wall of a tunnel, so that seismic advanced prediction technologies of TSP (Tunnel Seismic Prediction, Swiss Amberg Measurement Technology Company), TRT (True Reflection Tomography, American NSA Engineering Company) and the like can not be applied; (2) the tunnel boring machine is provided with a large amount of metal members and power supply cables which may produce huge electromagnetic interference, so that the detection effects of a ground penetrating radar method, a time domain electromagnetic method and the like are extremely unsatisfactory; and (3) when the tunnel boring machine is used for construction, about two hours for overhauling is needed every day, at the moment, a cutter head of the tunnel boring machine retreats for 1-2 m, and this is a unique link for advanced geological prediction, but the space is narrow and the time is relatively short. In general, the advanced geological prediction in the tunnel boring machine construction environment faces the problems of “narrow observation space, complex electromagnetic environment and relatively short detection time”.
At present, there are mainly a few technologies and instruments for advanced geological prediction of tunnel boring machine construction around the world as follows: (1) an advanced drill of the tunnel boring machine is utilized for boring, which has the defects that only the geological condition around a borehole can be disclosed, the geological condition within the whole range in front of the tunnel face can not be reflected, geological abnormal bodies are easily left out, and misinformation, misreporting and hidden hazards are caused; (2) a focusing induced polarization method BEAM (Bore-Tunneling Electrical Ahead Monitoring, German Geohydraulic Data Company) system is utilized, but the BEAM technology can only be used for qualitatively judging whether a water-containing body exists within a certain range in front of the tunnel face, the positioning precision of the BEAM technology is easily disturbed by the on-site environment, and the BEAM technology can not be used for estimating and predicting the water quantity; (3) a seismic reflection method ISIS (Integrated Seismic Imaging System, German GFZ Company) system is utilized, in view of the observation manner of the ISIS, a traditional VSP (Vertical Seismic Profiling) manner is adopted, then large-scale geological abnormal bodies such as faults can be detected, but the water-containing body can not be identified, and how to remove the vibration interference in the tunnel boring machine construction is a problem; and (4) a seismic softground probing SSP (Sonic Softground Probing, German Herrenknecht Company) system is a special seismic wave system for boulder probing in softground, and the probing distance generally does not exceed 40 m, so the application range of the system is limited. Moreover, the document HSP Sound Wave Reflection Method Geological Advanced Prediction of TBM Construction, the patent Device for Advanced Geological Prediction with Vibration Signals in TBM Method Construction and Using Method Thereof and the patent TBM Construction Tunnel Forward Three-Dimensional Induced Polarization Method Advanced Detection Device System and Method respectively referred to the technical schemes of carrying seismic wave and induced polarization detection devices on tunnel boring machines to carry out advanced geological detection, the adopted detection methods are simplex, and the application range and detection object of each detection method are different from those of the other one, so that various unfavorable geological conditions in front of the tunnel face can not be comprehensively and accurately detected and predicted.
Aiming at the complex environment of the tunnel boring machine construction, in order to detect unfavorable geological bodies such as faults, fractured rock masses and karsts in front of tunnel faces and quantitatively detect the position and quantity of underground water, it is impractical to singly adopt a certain geophysical method. Through investigation and empirical analysis of existing technologies, three following geophysical detection methods are needed for comprehensive detection and joint inversion interpretation, so as to reduce the multiplicity and improve the detection effect:    (1) a seismic wave advanced detection technology: the detection distance of this method is relatively far (more than 100 meters), and this method has a good effect of detecting potential water-containing structures of faults, karst caves, underground rivers and the like;    (2) an induced polarization method advanced detection technology: researches discover that, this method has a good effect of quantitatively predicting the water quantity and spatial position of a water-containing body; and    (3) a borehole ground penetrating radar method advanced detection technology: according to this method, a borehole is drilled, a borehole radar antenna is transmitted to a borehole to implement detection, the resolution of a borehole ground penetrating radar is high, and the detection radius is relatively small, so that this method is applicable to fine detection of geological conditions in front of tunnel boring machine construction faces.
In general, the unfavorable geological advanced prediction technologies and instruments of the tunnel boring machine construction are still at the initial stage, and have the following main problems:    (1) the observation space in the tunnel boring machine construction environment is very narrow, and only a space of 1-2 meters between a cutter head and a tunnel face during overhauling can be utilized, so how the space is utilized for effective observation by the detection technologies of a seismic method, an electrical method, an electromagnetic method and the like is a problem;    (2) since the tunnel boring machine is a complex mechanical system and has relatively high requirements for integration and automation of advanced detection equipment, a carrying problem and an automation problem of advanced detection instruments need to be solved; and    (3) since the cutter head needs to rotate to realize rock breaking and digging in the tunnel boring machine construction, the communication between an advanced detection instrument and an excitation/acquisition device arranged on the cutter head, how to avoid winding of electro-hydraulic supply pipelines in the rotating state of the cutter head and how to realize good wiring are problems.